Field
Embodiments described herein generally relate to a substrate temperature monitoring system.
Description of the Related Art
Flat panel displays (FPD) are commonly used for active matrix displays such as computer and television monitors, personal digital assistants (PDAs), and cell phones, as well as solar cells and the like. Plasma enhanced chemical vapor deposition (PECVD) may be employed in flat panel display fabrication to deposit thin film on a substrate. PECVD is generally accomplished by executing a precursor gas into a plasma within a vacuum process chamber and depositing a film on a substrate from the excited precursor gas.
During deposition, the plasma within the vacuum processing chamber heats the substrate and the substrate support assembly. The plasma may cause the temperature of the substrate support assembly to have a temporal temperature increase or spike (e.g., about 30-50° C. increase, or 20%-30% temperature increase from 150° C.). Such a large temperature increase of the substrate support assembly undesirably causes process variation.
Thus, there is a need for an improved substrate temperature monitoring system for a substrate support assembly.